Question

The area of a rectangle with length 20cm is 220sq.cm. If each of its side is doubled, what will be its new area?

Answer 1

hello,

we indicate with b and h the breadth and the height of the rectangle.
we calculate b:
b=A:h=220:20=11 cm

now, we calculate the breadth and the height of the new rectangle:
b'=2b=2×11=22 cm
h'=2h=2×20=40 cm
we calculate the new area:
A=b×h=22×40=880 cm²

bye :-)